The purpose of this supplemental application is to expand the work that we began in 2003 comparing a peer education intervention to an individually-focused intervention among street-recruited injection drug users (IDUs). The expanded scope will include 336 methamphetamine (meth) IDUs who will be given the same interventions as in the parent grant. The continued increase in HCV and HIV, along with the rise in meth use, underscores the importance of this effort. The peer education intervention emphasizes the use of peeer educators as leaders in the community to affect change in their netowrk. The individually-focused intervention uses community workers and offers a systematic means for identifying and accessing social networks of active drug injectors. The aims of this supplemental application are the same as those of the parent grant: 1. To compare the effectiveness of a peer education intervention vs. an individually-focused intervention in increasing knowledge about HCV and HIV among meth users; 2. To compare the effectiveness of the two interventions in improving self-efficacy regarding reducing HCV and HIV risk behaviors among meth users; and 3. To compare the two intervention approaches in reducing HCV/HIV- related risk behaviors among meth users. Over two years, 168 index members will be recruited through street outreach. Each index member will be required to bring in one eligible network member to participate in baseline and 6-month interviews, for a total of 336 meth IDUs. Next, index members will be randomly assigned to either the individually-focused or peer education intervention. Index members in peer education will receive 5 group-level sessions, and those in the individually-focused arm will receive 5 individual sessions. Outcomes include HCV/HIV knowledge, self-efficacy to reduce HCV/HIV risk, and HCV and HIV risk behaviors. We hypothesize that network members in the peer education arm will be more knowledgeable about HCV/HIV than network members in the individually-focused arm, that network members in the peer education intervention will increase their self-efficacy more than network members in the individually-focused arm, and that network members from the peer education intervention will demonstrate greater reductions in HCV/HIV risk behaviors than network members from the individually- focused intervention. [unreadable] [unreadable] [unreadable]